diff --git a/liteflow-core/pom.xml b/liteflow-core/pom.xml
index 745417a84..04ab79e44 100644
--- a/liteflow-core/pom.xml
+++ b/liteflow-core/pom.xml
@@ -9,7 +9,7 @@
     <parent>
 		<groupId>com.yomahub</groupId>
 		<artifactId>liteflow</artifactId>
-		<version>2.5.5</version>
+		<version>2.5.6</version>
 	</parent>
 
 	<dependencies>
diff --git a/liteflow-core/src/main/java/com/yomahub/liteflow/entity/data/DataBus.java b/liteflow-core/src/main/java/com/yomahub/liteflow/entity/data/DataBus.java
index 5e072fad4..8051fc0bd 100644
--- a/liteflow-core/src/main/java/com/yomahub/liteflow/entity/data/DataBus.java
+++ b/liteflow-core/src/main/java/com/yomahub/liteflow/entity/data/DataBus.java
@@ -7,15 +7,18 @@
  */
 package com.yomahub.liteflow.entity.data;
 
-import java.util.concurrent.atomic.AtomicInteger;
-
 import cn.hutool.core.util.ObjectUtil;
-import com.yomahub.liteflow.exception.ConfigErrorException;
 import com.yomahub.liteflow.property.LiteflowConfig;
 import com.yomahub.liteflow.util.SpringAware;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicReferenceArray;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
 /**
  * 数据BUS，主要用来管理Slot，用以分配和回收
  * @author Bryan.Zhang
@@ -26,7 +29,9 @@ public class DataBus {
 
 	public static AtomicInteger OCCUPY_COUNT = new AtomicInteger(0);
 
-	private static Slot[] slots;
+	private static AtomicReferenceArray<Slot> SLOTS;
+
+	private static ConcurrentLinkedQueue<Integer> QUEUE;
 
 	static {
 		LiteflowConfig liteflowConfig = SpringAware.getBean(LiteflowConfig.class);
@@ -36,20 +41,22 @@ public class DataBus {
 			liteflowConfig = new LiteflowConfig();
 		}
 		int slotSize = liteflowConfig.getSlotSize();
-		slots = new Slot[slotSize];
+
+		SLOTS = new AtomicReferenceArray<>(slotSize);
+
+		QUEUE = IntStream.range(0, slotSize - 1).boxed().collect(Collectors.toCollection(ConcurrentLinkedQueue::new));
 	}
 
-	public synchronized static int offerSlot(Class<? extends Slot> slotClazz){
-		try{
-			for(int i = 0; i < slots.length; i++){
-				if(ObjectUtil.isNull(slots[i])){
-					slots[i] = slotClazz.newInstance();
-					OCCUPY_COUNT.incrementAndGet();
-					return i;
-				}
+	public static int offerSlot(Class<? extends Slot> slotClazz) {
+		try {
+			Slot slot = slotClazz.newInstance();
+			Integer slotIndex = QUEUE.poll();
+			if (ObjectUtil.isNotNull(slotIndex) && SLOTS.compareAndSet(slotIndex, null, slot)) {
+				OCCUPY_COUNT.incrementAndGet();
+				return slotIndex;
 			}
-		}catch(Exception e){
-			LOG.error("offer slot error",e);
+		} catch (Exception e) {
+			LOG.error("offer slot error", e);
 			return -1;
 		}
 		return -1;
@@ -57,13 +64,14 @@ public class DataBus {
 
 	@SuppressWarnings("unchecked")
 	public static <T extends Slot> T getSlot(int slotIndex){
-		return (T)slots[slotIndex];
+		return (T)SLOTS.get(slotIndex);
 	}
 
 	public static void releaseSlot(int slotIndex){
-		if(ObjectUtil.isNotNull(slots[slotIndex])){
-			LOG.info("[{}]:slot[{}] released",slots[slotIndex].getRequestId(),slotIndex);
-			slots[slotIndex] = null;
+		if(ObjectUtil.isNotNull(SLOTS.get(slotIndex))){
+			LOG.info("[{}]:slot[{}] released",SLOTS.get(slotIndex).getRequestId(),slotIndex);
+			SLOTS.set(slotIndex, null);
+			QUEUE.add(slotIndex);
 			OCCUPY_COUNT.decrementAndGet();
 		}else{
 			LOG.warn("slot[{}] already has been released",slotIndex);
diff --git a/liteflow-core/src/main/java/com/yomahub/liteflow/entity/flow/Node.java b/liteflow-core/src/main/java/com/yomahub/liteflow/entity/flow/Node.java
index 705196eb5..5ebf1f45e 100644
--- a/liteflow-core/src/main/java/com/yomahub/liteflow/entity/flow/Node.java
+++ b/liteflow-core/src/main/java/com/yomahub/liteflow/entity/flow/Node.java
@@ -36,7 +36,7 @@ public class Node implements Executable{
 
 	private NodeComponent instance;
 
-	private Map<String, Executable> condNodeMap = new HashMap<String, Executable>();
+	private final Map<String, Executable> condNodeMap = new HashMap<>();
 
 	public Node(){
 
diff --git a/liteflow-core/src/main/java/com/yomahub/liteflow/flow/FlowBus.java b/liteflow-core/src/main/java/com/yomahub/liteflow/flow/FlowBus.java
index 0153b019d..f29114139 100644
--- a/liteflow-core/src/main/java/com/yomahub/liteflow/flow/FlowBus.java
+++ b/liteflow-core/src/main/java/com/yomahub/liteflow/flow/FlowBus.java
@@ -1,6 +1,7 @@
 /**
  * <p>Title: liteflow</p>
  * <p>Description: 轻量级的组件式流程框架</p>
+ *
  * @author Bryan.Zhang
  * @email weenyc31@163.com
  * @Date 2020/4/1
@@ -13,7 +14,11 @@ import cn.hutool.core.util.StrUtil;
 import com.yomahub.liteflow.core.NodeComponent;
 import com.yomahub.liteflow.entity.flow.Chain;
 import com.yomahub.liteflow.entity.flow.Node;
+import com.yomahub.liteflow.enums.FlowParserTypeEnum;
 import com.yomahub.liteflow.exception.ComponentCannotRegisterException;
+import com.yomahub.liteflow.parser.LocalJsonFlowParser;
+import com.yomahub.liteflow.parser.LocalXmlFlowParser;
+import com.yomahub.liteflow.parser.LocalYmlFlowParser;
 import com.yomahub.liteflow.util.SpringAware;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -27,75 +32,85 @@ import java.util.Map;
  */
 public class FlowBus {
 
-	private static final Logger LOG = LoggerFactory.getLogger(FlowBus.class);
+    private static final Logger LOG = LoggerFactory.getLogger(FlowBus.class);
 
-	private static final Map<String, Chain> chainMap = new HashMap<>();
+    private static final Map<String, Chain> chainMap = new HashMap<>();
 
-	private static final Map<String, Node> nodeMap = new HashMap<>();
-	
-	private FlowBus() {
-	}
-	
-	public static Chain getChain(String id) throws Exception {
-		if (MapUtil.isEmpty(chainMap)) {
-			throw new Exception("please config the rule first");
-		}
-		return chainMap.get(id);
-	}
+    private static final Map<String, Node> nodeMap = new HashMap<>();
 
-	public static void addChain(String name,Chain chain){
-		chainMap.put(name, chain);
-	}
+    private FlowBus() {
+    }
 
-	public static boolean containChain(String chainId){
-		return chainMap.containsKey(chainId);
-	}
+    public static Chain getChain(String id) throws Exception {
+        if (MapUtil.isEmpty(chainMap)) {
+            throw new Exception("please config the rule first");
+        }
+        return chainMap.get(id);
+    }
 
-	public static boolean needInit() {
-		return MapUtil.isEmpty(chainMap);
-	}
+    public static void addChain(String name, Chain chain) {
+        chainMap.put(name, chain);
+    }
 
-	public static boolean containNode(String nodeId) {
-		return nodeMap.containsKey(nodeId);
-	}
+    public static boolean containChain(String chainId) {
+        return chainMap.containsKey(chainId);
+    }
 
-	public static void addNode(String nodeId, Node node) {
-		if (containNode(nodeId)) return;
-		nodeMap.put(nodeId, node);
-	}
+    public static boolean needInit() {
+        return MapUtil.isEmpty(chainMap);
+    }
 
-	public static void addNode(String nodeId, String cmpClazzStr) throws Exception{
-		if (containNode(nodeId)) return;
-		Class<NodeComponent> cmpClazz = (Class<NodeComponent>)Class.forName(cmpClazzStr);
-		addNode(nodeId, cmpClazz);
-	}
+    public static boolean containNode(String nodeId) {
+        return nodeMap.containsKey(nodeId);
+    }
 
-	public static void addNode(String nodeId, Class<? extends NodeComponent> cmpClazz){
-		if (containNode(nodeId)) return;
-		try{
-			//以node方式配置，本质上是为了适配无spring的环境，如果有spring环境，其实不用这么配置
-			//这里的逻辑是判断是否能从spring上下文中取到，如果没有spring，则就是new instance了
-			NodeComponent cmpInstance = SpringAware.registerOrGet(cmpClazz);
-			if (ObjectUtil.isNull(cmpInstance)) {
-				LOG.warn("couldn't find component class [{}] from spring context", cmpClazz.getName());
-				cmpInstance = cmpClazz.newInstance();
-			}
-			cmpInstance.setNodeId(nodeId);
-			cmpInstance.setSelf(cmpInstance);
-			nodeMap.put(nodeId, new Node(nodeId, cmpClazz.getName(), cmpInstance));
-		}catch (Exception e){
-			String error = StrUtil.format("component[{}] register error", cmpClazz.getName());
-			LOG.error(error, e);
-			throw new ComponentCannotRegisterException(error);
-		}
-	}
+    public static void addNode(String nodeId, Node node) {
+        if (containNode(nodeId)) return;
+        nodeMap.put(nodeId, node);
+    }
 
-	public static Node getNode(String nodeId) {
-		return nodeMap.get(nodeId);
-	}
+    public static void addNode(String nodeId, String cmpClazzStr) throws Exception {
+        if (containNode(nodeId)) return;
+        Class<NodeComponent> cmpClazz = (Class<NodeComponent>) Class.forName(cmpClazzStr);
+        addNode(nodeId, cmpClazz);
+    }
 
-	public static void cleanCache(){
-		chainMap.clear();
-		nodeMap.clear();
-	}
+    public static void addNode(String nodeId, Class<? extends NodeComponent> cmpClazz) {
+        if (containNode(nodeId)) return;
+        try {
+            //以node方式配置，本质上是为了适配无spring的环境，如果有spring环境，其实不用这么配置
+            //这里的逻辑是判断是否能从spring上下文中取到，如果没有spring，则就是new instance了
+            NodeComponent cmpInstance = SpringAware.registerOrGet(cmpClazz);
+            if (ObjectUtil.isNull(cmpInstance)) {
+                LOG.warn("couldn't find component class [{}] from spring context", cmpClazz.getName());
+                cmpInstance = cmpClazz.newInstance();
+            }
+            cmpInstance.setNodeId(nodeId);
+            cmpInstance.setSelf(cmpInstance);
+            nodeMap.put(nodeId, new Node(nodeId, cmpClazz.getName(), cmpInstance));
+        } catch (Exception e) {
+            String error = StrUtil.format("component[{}] register error", cmpClazz.getName());
+            LOG.error(error, e);
+            throw new ComponentCannotRegisterException(error);
+        }
+    }
+
+    public static Node getNode(String nodeId) {
+        return nodeMap.get(nodeId);
+    }
+
+    public static void cleanCache() {
+        chainMap.clear();
+        nodeMap.clear();
+    }
+
+    public static void refreshFlowMetaData(FlowParserTypeEnum type, String content) throws Exception {
+        if (type.equals(FlowParserTypeEnum.TYPE_XML)) {
+            new LocalXmlFlowParser().parse(content);
+        } else if (type.equals(FlowParserTypeEnum.TYPE_JSON)) {
+            new LocalJsonFlowParser().parse(content);
+        } else if (type.equals(FlowParserTypeEnum.TYPE_YML)) {
+            new LocalYmlFlowParser().parse(content);
+        }
+    }
 }
diff --git a/liteflow-core/src/main/java/com/yomahub/liteflow/parser/FlowParser.java b/liteflow-core/src/main/java/com/yomahub/liteflow/parser/FlowParser.java
index 7d89d3443..537a0cfa9 100644
--- a/liteflow-core/src/main/java/com/yomahub/liteflow/parser/FlowParser.java
+++ b/liteflow-core/src/main/java/com/yomahub/liteflow/parser/FlowParser.java
@@ -29,7 +29,7 @@ public abstract class FlowParser {
     public abstract void parse(String content) throws Exception ;
 
     //条件节点的正则解析
-    public static RegexEntity parseNodeStr(String str) {
+    public RegexEntity parseNodeStr(String str) {
         List<String> list = new ArrayList<String>();
         Pattern p = Pattern.compile("[^\\)\\(]+");
         Matcher m = p.matcher(str);
diff --git a/liteflow-core/src/main/java/com/yomahub/liteflow/parser/XmlFlowParser.java b/liteflow-core/src/main/java/com/yomahub/liteflow/parser/XmlFlowParser.java
index fdab15e00..e7c4d1f08 100644
--- a/liteflow-core/src/main/java/com/yomahub/liteflow/parser/XmlFlowParser.java
+++ b/liteflow-core/src/main/java/com/yomahub/liteflow/parser/XmlFlowParser.java
@@ -9,6 +9,7 @@ import com.yomahub.liteflow.entity.flow.Condition;
 import com.yomahub.liteflow.entity.flow.Executable;
 import com.yomahub.liteflow.entity.flow.Node;
 import com.yomahub.liteflow.exception.ExecutableItemNotFoundException;
+import com.yomahub.liteflow.exception.ParseException;
 import com.yomahub.liteflow.flow.FlowBus;
 import com.yomahub.liteflow.spring.ComponentScanner;
 import com.yomahub.liteflow.util.SpringAware;
@@ -57,7 +58,9 @@ public abstract class XmlFlowParser extends FlowParser{
 				}
 			} else {
 				for (Entry<String, NodeComponent> componentEntry : ComponentScanner.nodeComponentMap.entrySet()) {
-					FlowBus.addNode(componentEntry.getKey(), new Node(componentEntry.getKey(), componentEntry.getValue().getClass().getName(), componentEntry.getValue()));
+					if (!FlowBus.containNode(componentEntry.getKey())){
+						FlowBus.addNode(componentEntry.getKey(), new Node(componentEntry.getKey(), componentEntry.getValue().getClass().getName(), componentEntry.getValue()));
+					}
 				}
 			}
 
@@ -67,8 +70,9 @@ public abstract class XmlFlowParser extends FlowParser{
 				parseOneChain(e);
 			}
 		} catch (Exception e) {
-			LOG.error("FlowParser parser exception", e);
-			throw e;
+			String errorMsg = "FlowParser parser exception";
+			LOG.error(errorMsg, e);
+			throw new ParseException(errorMsg);
 		}
 	}
 
diff --git a/liteflow-core/src/main/java/com/yomahub/liteflow/parser/ZookeeperXmlFlowParser.java b/liteflow-core/src/main/java/com/yomahub/liteflow/parser/ZookeeperXmlFlowParser.java
index a5ac76a7d..5496c10c6 100644
--- a/liteflow-core/src/main/java/com/yomahub/liteflow/parser/ZookeeperXmlFlowParser.java
+++ b/liteflow-core/src/main/java/com/yomahub/liteflow/parser/ZookeeperXmlFlowParser.java
@@ -4,6 +4,7 @@ import java.text.MessageFormat;
 
 import cn.hutool.core.util.StrUtil;
 
+import com.yomahub.liteflow.flow.FlowBus;
 import org.apache.curator.framework.CuratorFramework;
 import org.apache.curator.framework.CuratorFrameworkFactory;
 import org.apache.curator.framework.recipes.cache.NodeCache;
@@ -57,13 +58,11 @@ public class ZookeeperXmlFlowParser extends XmlFlowParser{
         final NodeCache cache = new NodeCache(client,nodePath);
         cache.start();
 
-        cache.getListenable().addListener(new NodeCacheListener() {
-            @Override
-            public void nodeChanged() throws Exception {
-                String content = new String(cache.getCurrentData().getData());
-                LOG.info("stating load flow config....");
-                parse(content);
-            }
+        cache.getListenable().addListener(() -> {
+            String content1 = new String(cache.getCurrentData().getData());
+            LOG.info("stating load flow config....");
+            FlowBus.cleanCache();
+            parse(content1);
         });
 	}
 }
diff --git a/liteflow-spring-boot-starter/pom.xml b/liteflow-spring-boot-starter/pom.xml
index ae8f68100..96f36a864 100644
--- a/liteflow-spring-boot-starter/pom.xml
+++ b/liteflow-spring-boot-starter/pom.xml
@@ -10,7 +10,7 @@
     <parent>
         <artifactId>liteflow</artifactId>
         <groupId>com.yomahub</groupId>
-        <version>2.5.5</version>
+        <version>2.5.6</version>
     </parent>
 
     <dependencies>
diff --git a/liteflow-test-spring/pom.xml b/liteflow-test-spring/pom.xml
index e24e07f74..1b5d89200 100644
--- a/liteflow-test-spring/pom.xml
+++ b/liteflow-test-spring/pom.xml
@@ -9,7 +9,7 @@
     <parent>
         <artifactId>liteflow</artifactId>
         <groupId>com.yomahub</groupId>
-        <version>2.5.5</version>
+        <version>2.5.6</version>
     </parent>
 
     <dependencies>
diff --git a/liteflow-test-springboot/pom.xml b/liteflow-test-springboot/pom.xml
index 9899d523a..734c6e906 100644
--- a/liteflow-test-springboot/pom.xml
+++ b/liteflow-test-springboot/pom.xml
@@ -9,7 +9,7 @@
     <parent>
         <artifactId>liteflow</artifactId>
         <groupId>com.yomahub</groupId>
-        <version>2.5.5</version>
+        <version>2.5.6</version>
     </parent>
 
     <dependencyManagement>
diff --git a/pom.xml b/pom.xml
index 21289929f..233d7ffb1 100644
--- a/pom.xml
+++ b/pom.xml
@@ -5,7 +5,7 @@
 	<groupId>com.yomahub</groupId>
     <artifactId>liteflow</artifactId>
     <packaging>pom</packaging>
-    <version>2.5.5</version>
+    <version>2.5.6</version>
 	<name>liteflow</name>
 	<description>a lightweight and practical micro-process framework</description>
 	<url>https://github.com/bryan31/liteflow</url>